Like most guys, I have been a 'one-shot' dude for most of my life. I started masturbating when I was about 12 and for many years it was the typical stroke fast to cum quickly technique. But thanks to the Internet and books, I learned that it is possible to cum several times in a session. This does take some 'training' since the urge is always to stroke to climax.
When I get extremely horny, I usually get out a favorite porn tape for inspiration. I strip and lie back on the couch and fondle my glans until I get about half hard. I then get out the bottle of lube (usually I use Astroglide) and get my cock all wet. Sometimes when I am really horny, a butt plug really enhances the session. (I have ejaculated with just anal penetration alone).
I switch between a normal stroking of the shaft and massaging the glans with my thumb. When I get to the point of no return, I just ever so slightly tease myself with a light touch until I feel that pressure build to where I will squirt.
Then I stop and let the climax take place without any further touching, holding my hand over the glans to catch the ejaculate.
I then rub the ejaculate all over my shaft - the slippery warmth feels great, and I begin to slowly stroke again, just keeping myself at the point of no return once again. The sensitivity is really high at this point. After a few minutes I will again just let it go over the edge and climax again (stopping all motion).
Sometimes I can do this four or five times over a span of maybe 10 minutes. Usually by the third climax, there is no more ejaculate but can still climax.
When the sensitivity level drops off and I am ready for a last climax, I will stroke rapidly and with a firm grip all the way thru a final climax, which leaves me totally drained and satisfied.